Shaft coupler



A ril 8, 1958 R. c. RUSSELL SHAFT COUPLER Filed May 20, 1955 JNVENTOR 4 ROBERT c. RUSSELL ATTORNEY 2,829,885 SHAFT COUPLER Robert C. Russell, Shaker Heights, Eaton Manufacturing Company, corporation of Ohio Application May 20, 1955, Serial No. 509,821 4 Claims. (Cl. 268-424) Ohio, assignor to Cleveland, Ohio, a

posable between drivmg and driven rotary members of such apparatus having a coil spring engaging each of the parts thereon so as to wind up or be self energizing motor torque transfer in one direction of rotation and to unwind or be self to heat engendered in slippage of the parts of the coupler under high loads so window and its upper enclosure while the actuating switch for the window is accidently or inadvertantly turned on so as to raise the window. Without limiting means in the power circuit of States Patent fer of torque in one direction of rotation to a predetermined proportion of full motor torque while assuring full torque transfer for an opposite direction of rotation.

It is a further object of this invention to provide a shaft coupler that automatically immediately prevents transmission movement of the driven member when the driven member encounters a load in excess of a predetermined shp the driving member after a brief period of operation at overload.

It is a further object of this invention to provide a shaft slip coupler which incorporates means for damping torsional vibrations.

It is a yet further object of the invention to provide a slip shaft coupler as applied to window regulating apparatus for vehicles or the like permitting of limited torque transmission in the closing of a window and providing full torque transmission in an opening operation of the window.

Other and further objects and advantages of this invention will appear from a perusal of the following detailed description taken with the accompanying drawings in which:

Fig. 1 depicts the clutch of this invention as applied to a window operating apparatus,

Fig. 2 is an end view of the clutch shown in Fig. 1,

Fig. 3 depicts the clutch of this invention in a partial sectional view, and

Fig. 4 depicts an end view of the clutch in Fig. 3.

Referring now more particularly to Fig. 1 of the drawing 10 represents a window pane of an automobile or 12 in some suitable manner as by a pair of angular plates 18 and 20 pivotally secured intermediate the lengths thereof are provided and each has a roller movable along the track 14 attached at its upper end. Arm 18 is pivotal at its other end about a fixed stub shaft pivot 22 and the other end of arm 20 is movable along a fixed track 24 by means of a roller attached to the end of the arm.

Arm 18 is urged in a counterclockwise direction as viewed in Fig. 1 of the drawing by a spirally wound counterbalance spring 26 having one end anchored in a slot in stub shaft 22, fixedly secured to arm 18, and its other end secured to a stationary member forming a part of a fixed bracket 28. The tendency of spring 26 in urging arm 18 in a counterclockwise rotation is to elevate window 10. The torque imparted by spring 26, however, is only suflicient to overcome the force of weight of window 10 and is insufiicient to elevate the window of itself.

Bracket 28 provides support for a gear mechanism 31 including a pinion gear 30 which engages a gear sector 32 fixedly secured with arm 18 for rotation therewith about the pivot for shaft 22.

Pinion 30 is driven 32, arms 18 and 20 and window 10 in two directions. In lowering the window 10, coupler 36 provides full torque of motor 36 while in elevating window 10, coupler 36 provides only a fraction of full torque of motor 34; the torque being sutficient to raise window 10 against only moderate resistance. In the event that window 10 encounters large resistance to elevation, coupler 36 provides slip or relative rotation'between its input and output-members to alleviate the stress andstrainon parts of the window actuator and that affording the resistance to elevation.

Referring nowmoreparticularlytoFig. 3 for a more detailed description'of the shaft'coupler, 38-represents the input-shaftto 'thecoupler which may also bethe output shaft of motor 34 and 40 represents the output shaft of the'coupler. An inputmember 42 rotatable withshaft 38 in provided having a first reduced cylindrical portion '44 and a second reduced portion 46. An output member including a sleeve element 48 is provided having a reduced cylindrical portion 50 of the same'diameter'as'portion 44 and axially adjacent thereto and with'portion '46 telescoped thereby. Reduced portions 44 and 50 taken togetherprovidean annular recess adaptable to receive a coil spring 52 having a portion 43 at one extremity extending axially in a notch'in member 42 for driving engagement therewith and with the coiled body'thereof extending axially along the recess and wound tightly upon the mentionedreduced'portions 44 and50 in a'right hand sense if the worm gear of mechanism 31 has a'left hand thread or in a left hand sense if'the worm gear is right handedly threaded for a purpose'tobe described. It is to be understood that in acordance'with the invention it is necessary to wind coil spring 52 in a sense soas to tend to unwind as the window is being elevated by the actuators.

Members 42 and 43 are preferably made of cast iron or steel and coil spring-52 of spring bronze although many other materials may also be employed with satisfactory results. In one application of the invention it is paramount that the expansion coefficient of coil '52 be considerably greater thanthat of'member 48. As an example, in one embodiment of the invention member 48 is made of cast iron with a coefiicient of expansion equal to .000556 unit per unit length per 100 F. and coil 52 is made of bronze having a-coefiicient of expansion equal to .000986 unit per unit length per 100 F.

Portion 48 of the output member is attached in some suitable manner to a resilient annular member 54 preferably of synthetic rubber which in turn is attached to an output member 56 rotatable with output shaft 40.

In operaion the shaft of motor 34 rotates to initiate operation of the window actuating mechanism. Assuming the coil spring 52 to be wound in a right hand sense and the worm gear of mechanism 31 to be left handedly threaded, a clockwise rotation of the shaft of motor 34 as viewed from the rear and hereinafter referred to as the forward direction is effective to elevate window 10 through "the actuating mechanism in -a well-known manner. Reverse rotation of motor 34 on the other hand is effective to lower window 10.

In the event that the window mechanism should ent counter an unusual resistance to movement as by an obstruction in its path of elevation, coupler 36 is operative to transmit only a fraction of the full torque of motor 34. Spring 52 under the circumstances being frictionally engaged to driven member 48 will tend to unwind and therefore to increase its diameter and consequently to reduce the frictional engagement mentioned. The

effect of reduced frictional engagement, of course, is to reduce the torque transferred.

It is readily understood that the above described events result instantaneously to alleviate stresses that may re- 'sult in the window actuating mechanism as well as to alleviate any harmful forces acting on'the obstruction in- 'terposed in the path of the window.

In the event that the resistance to elevation of the window should persist and'that energization of motor 34 is mainainedit is noted'that provision is made for further decrease in torque transfer through coupler 36 to alleviate the parts mentioned. Underthese circumstances rotation of member relative to spring 52 is effective to :engenderconsiderable heat because of the friction therebetween. Also the heat energy is effective to expand coil 52 considerably more than member 48 by virtue of the different coefficients of expansion of the different compositions thereof to provide a clearance between the engaging members and consequently to further diminish or eliminate the frictional engagement therebetween.

It is also readily understood that upon reverse rotation of motor 15 coil 52'has a tendency to wind up on the member 48 so as to increase the frictional engagement therebetween to provide the transfer of full motor torque through coupler 36. As such a sticking of the window in a closed position due to ice or other foreign matter can be overcome and a proper lowering effected.

For the purpose of effecting smooth even performance of the coupler 36 a torsional vibration absorbing memoer 54 of some suitable resilient material, such as rubber, is provided'inthe power flow circuit of the coupler. Impulses or vibrations are absorbed therein to reduce the damaging effect thereof on component parts of the actuating mechanism and the window itself.

Another feature of the shaft coupler of the present invention resides in the accommodation thereof to driving and driven shafts that are not in precise axial alignment. Small deviations are taken up by spring 52 and resilient member 54 was toprevent damaging stresses on any of the components of theapparatus.

While the present invention has been described with reference to certain specific embodiments thereof, it is readily apparent to those skilled in the art that it is susceptible to numbers variations and modifications without deviating from the spirit or scope of the invention. It is accordingly intended to cover all such variations and modifications 'in the appended claims.

' What I claim is:

l. A window actuating apparatus comprising means including a first shaft'for elevating a window in response to rotation of said shaft in a first direction and for lowering said window in response to rotation of said shaft in asecond direction, a reversible motor having an output shaft, a coupler disposed between said first shaft and said output shaft, said coupler comprising a flanged sleeve element'fixed to said output shaft, a resilient sleeve having end surfaces and an inside surface, one of said end surfaces and said inside surface being bonded to said flanged sleeve element, a pair of axially adjacent rotatable members, one of said axially adjacent rotatable members being bonded to the other end surface of said resilient sleeve and the other of said axially adjacent rotatable members being fixed to said output shaft, said rotatable members having axially adjacent, radially reduced portions of equal diameter to form an axially extending annular recess, a coil spring located in said recess in frictional engagement with each of said members and having driving engagement with one of said members, said coil spring being of different composition from that of at least one of said members and having a coefficient of expansion greater than the coefficient of expansion of at least one of said members of different composition thereto, and said coil spring .being wound so as to advance when rotated in said first direction whereby torque transferred by said coupler is reduced in response to resistance to elevation .of said window.

.2. A window actuating apparatus according to claim 1 wherein the coefficient OfCXpEtl'lSlOfl of said spring is greater than that-of said members.

3. A window actuating apparatus according to claim 1 wherein the spring is secured to one of said members and wherein said'spring is operative to transmit fullmo- "tor torque for a lowering of window.

4.. A shaft coupler according to claim 3 wherein the the' cornposition of one of said member along the'por- 6 tions in contact with said spring is cast iron and the 2,167,373 Rocke July 25, 1939 composition of said spring is bronze. 2,324,145 Floraday July 13, 1943 2,643,750 Moulton June 30, 1953 References Cited in the file of this patent 2,579,392 B d M 25 1954 UNITED STATES PATENTS 5 2,685,949 Dunlap Aug. 10, 1954 2,052,961 Bonham Sept. 1, 1936 

